Suicide notes are essential for investigating the psychological state of suicide victims and establishing suicide prevention programs. Since only a few studies have attempted to identify the causes of suicidal behavior through suicide notes, it would be worth examining suicide notes. Quantitative research on suicide has offered a limited understanding of suicide. Results showed that the suicide victims had used the suicide note as a tool for their last communication. Further, in addition to neutral contents such as directions for funeral, the note often contained information about precipitating events that caused the suicidal ideation. Writing a suicide note seemed to help the victims consider concrete plans for suicide. This study proved that qualitative research on suicide notes would be helpful for researchers to understand suicide victims in depth, which cannot be achieved by quantitative methods alone. Based on these results, several suggestions for suicide prevention programs were discussed.
Qualitative Research ; Suicidal Ideation ; Suicide* ; Writing

We evaluated the effects of eye movements on facial feature recognition and memory retrieval. Thirty-eight participants learned the faces of five men, including features of the faces (eyes, nose, and mouth), and then performed a recognition memory task for partially manipulated versions of the faces. Bilateral eye movements, recognition accuracy, and mean fixation duration were evaluated. We observed differences in fixation durations for the manipulated features of the faces (eyes, F(3,78)=11.95, P<0.001; and mouth, F(3,78)=21.38, P<0.001). These findings demonstrate that eye movements have a functional role in learning and recognizing human faces. Furthermore, fixation durations increased for the manipulated facial features, suggesting that eye movements during recognition are not simply patterns produced during learning.
Eye Movements* ; Humans ; Learning ; Male ; Memory* ; Mouth ; Nose

We investigated event-related potentials (ERPs) to estimate the accuracy of eyewitness memories. Participants watched videos of vehicles being driven dangerously, from an anti-impaired driving initiative. The four-letter license plates of the vehicles were the target stimuli. Random numbers were presented while participants attempted to identify the license plate letters, and electroencephalograms were recorded. There was a significant difference in activity 300-500 milliseconds after stimulus onset, between target stimuli and random numbers. This finding contributes to establishing an eyewitness recognition model where different ERP components may reflect more explicit memory that is dissociable from recollection.
Electroencephalography ; Event-Related Potentials, P300 ; Evoked Potentials* ; Licensure ; Memory

This study was conducted to investigate whether memory accuracy can be assessed by analyzing electrophysiological responses (i.e., electroencephalography [EEG]) for retrieval cues related to the witnessed scene. Specifically, we examined the different patterns of EEG signals recorded during witnessed (target) and unwitnessed (lure) stimuli using event-related potential (ERP) analysis. Moreover, using multivariate pattern analysis, we also assessed how accurately single-trial EEG signals can classify target and lure stimuli. Participants watched a staged-crime video (theft crime), and the EEG signals evoked by the objects shown in the video were analyzed (n=56). Compared to the target stimulus, the lure stimulus elicited larger negative ERPs in frontal brain regions 300 to 500 milliseconds after the retrieval cue was presented. Furthermore, the EEG signals observed 450 to 500 milliseconds after the retrieval cue was presented showed the best classification performance related to eyewitness memory, with the mean classification accuracy being 56%. These results suggest that the knowledge and techniques of cognitive neuroscience can be used to estimate eyewitness memory accuracy.
Brain ; Classification ; Cognitive Neuroscience ; Cues ; Electroencephalography ; Evoked Potentials ; Machine Learning ; Memory

We investigated the neural correlates of accurate eyewitness memory retrieval using functional near-infrared spectroscopy. We analyzed oxygenated hemoglobin (HbO₂) concentration in the prefrontal cortex during eyewitness memory retrieval task and examined regional HbO₂ differences between observed objects (target) and unobserved objects (lure). We found that target objects elicited increased activation in the bilateral ventrolateral prefrontal cortex, which is known for monitoring retrieval processing via bottom-up attentional processing. Our results suggest bottom-up attentional mechanisms could be different during accurate eyewitness memory retrieval. These findings indicate that investigating retrieval mechanisms using functional nearinfrared spectroscopy might be useful for establishing an accurate eyewitness recognition model.
Cognitive Neuroscience ; Memory ; Oxygen ; Prefrontal Cortex ; Spectroscopy, Near-Infrared ; Spectrum Analysis

This study was conducted to investigate whether memory accuracy can be assessed by analyzing electrophysiological responses (i.e., electroencephalography [EEG]) for retrieval cues related to the witnessed scene. Specifically, we examined the different patterns of EEG signals recorded during witnessed (target) and unwitnessed (lure) stimuli using event-related potential (ERP) analysis. Moreover, using multivariate pattern analysis, we also assessed how accurately single-trial EEG signals can classify target and lure stimuli. Participants watched a staged-crime video (theft crime), and the EEG signals evoked by the objects shown in the video were analyzed (n=56). Compared to the target stimulus, the lure stimulus elicited larger negative ERPs in frontal brain regions 300 to 500 milliseconds after the retrieval cue was presented. Furthermore, the EEG signals observed 450 to 500 milliseconds after the retrieval cue was presented showed the best classification performance related to eyewitness memory, with the mean classification accuracy being 56%. These results suggest that the knowledge and techniques of cognitive neuroscience can be used to estimate eyewitness memory accuracy.

We investigated the neural correlates of accurate eyewitness memory retrieval using functional near-infrared spectroscopy. We analyzed oxygenated hemoglobin (HbOâ‚‚) concentration in the prefrontal cortex during eyewitness memory retrieval task and examined regional HbOâ‚‚ differences between observed objects (target) and unobserved objects (lure). We found that target objects elicited increased activation in the bilateral ventrolateral prefrontal cortex, which is known for monitoring retrieval processing via bottom-up attentional processing. Our results suggest bottom-up attentional mechanisms could be different during accurate eyewitness memory retrieval. These findings indicate that investigating retrieval mechanisms using functional nearinfrared spectroscopy might be useful for establishing an accurate eyewitness recognition model.